Evolutionary implications of discordant clines across the Baltic Mytilus hybrid zone (Mytilus edulis and Mytilus trossulus)

Abstract The effects on the immune response of the mussels Mytilus edulis and Mytilus trossulus from of life-time exposure to marine pollution found in an industrial shipping port with a military history (Halifax Harbour, Nova Scotia, Canada) were investigated. Parameters measured included phagocytic activity, cellular production of hydrogen peroxide, number of circulating haemocytes, and cellular viability. Mussels sampled within Halifax Harbour had significantly reduced phagocytic activity and significantly reduced production of hydrogen peroxide in comparison with mussels sampled from a reference site outside of Halifax Harbour, indicating that pollution induced immunomodulation. No significant differences were found in number of circulating haemocytes or in cellular viability between mussels sampled within Halifax Harbour and mussels sampled outside Halifax Harbour. Results are discussed in terms of using a multi-assay approach for monitoring environmental pollution.

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Incomplete Reproductive Isolation in the Blue Mussel (Mytilus edulis and M. trossulus) Hybrid Zone in the Northwest Atlantic: Role of Gamete Interactions and Larval Viability

Biological Bulletin ◽

10.1086/bblv218n3p266 ◽

2010 ◽

Vol 218 (3) ◽

pp. 266-281 ◽

Cited By ~ 14

Author(s):

Marcelo B. B. Miranda ◽

David J. Innes ◽

Raymond J. Thompson

Keyword(s):

Reproductive Isolation ◽

Mytilus Edulis ◽

Hybrid Zone ◽

Blue Mussel ◽

Northwest Atlantic ◽

Gamete Interactions ◽

Incomplete Reproductive Isolation

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Interspecific mitochondrial DNA transfer and the colonization of Scandinavia by mice

Genetics Research ◽

10.1017/s0016672300026690 ◽

1987 ◽

Vol 49 (1) ◽

pp. 25-29 ◽

Cited By ~ 95

Author(s):

Ulf Gyllensten ◽

Allan C. Wilson

Keyword(s):

Mitochondrial Dna ◽

Hybrid Zone ◽

Restriction Enzymes ◽

Electrophoretic Analysis ◽

Nuclear Genes ◽

Mouse Population ◽

Apparent Lack ◽

North Germany ◽

Founder Event ◽

The Baltic

SummaryRestriction enzymes were used to search for genetic variability at 162 cleavage sites in mitochondrial DNA (mtDNA) purified from 22 mice caught at seven Swedish localities. Although all of these mice bear the nuclear genes of Mus musculus, they bear the mtDNA of M. domesticus exclusively. Yet, some of the Swedish localities are 750 km away from the hybrid zone between these two species. Furthermore, only one type of mtDNA was found at the seven Swedish localities; this type was found before at an eighth locality in Sweden as well as in Jutland north of the hybrid zone. The apparent lack of mtDNA divergence in the mouse population of Sweden contrasts with the extensive divergence usually found within other geographic areas in Europe, Africa and North America. Electrophoretic analysis of proteins encoded by nuclear genes indicates that the Swedish mice have lower average heterozygosity than Danish and Central European populations of musculus mice. These findings lead us to suggest that the source of the commensal mouse population in Sweden was a small propagule that originated from a population situated only a few kilometres to the east of the point at which the hybrid zone on the European mainland meets the Baltic Sea, namely on East Holstein. Such a founder event may have been associated with the spread of farming from north Germany into Sweden about 4000 years ago.

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